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DVD-Video is a consumer video format used to store digital video on DVD discs, and is currently the dominant consumer video format in Asia, North America, Europe, and Australia. Discs using the DVD-Video specification require a DVD drive and an MPEG-2 decoder (e.g., a DVD player, or a computer DVD drive with a software DVD player). Commercial DVD movies are encoded using a combination MPEG-2 compressed video and audio of varying formats (often multi-channel formats as described below). Typically, the data rate for DVD movies ranges from 3 Mbit/s to 9.5 Mbit/s, and the bit rate is usually adaptive. It was first available for retail around March 26, 1997. The DVD-Video specification was created by DVD Forum and can be obtained from DVD Format/Logo Licensing Corporation for a fee of $5,000.〔DVD FLLC (2009) ("DVD Format Book" ). Retrieved 2009-08-14.〕〔DVD FLLC (2009) ("How to Obtain DVD Format/Logo License (2005–2009)" ). Retrieved 2009-08-14.〕 The specification is not publicly available and every subscriber must sign a non-disclosure agreement. Certain information in the DVD Book is proprietary and confidential.〔 == Video data == To record moving pictures, DVD-Video uses either H.262/MPEG-2 Part 2 compression at up to 9.8 Mbit/s (9,800 kbit/s) or MPEG-1 Part 2 compression at up to 1.856 Mbit/s (1,856 kbit/s). DVD-Video supports video with a bit depth of 8-bits per color YCbCr with 4:2:0 chroma subsampling. The following formats are allowed for H.262/MPEG-2 Part 2 video〔(【引用サイトリンク】 title=What is DVD? )〕: * At a display rate of 25 frames per second, interlaced (commonly used in regions with 50 Hz image scanning frequency): : 720×576 pixels (same resolution as D-1) : 704×576 pixels : 352×576 pixels (same as the China Video Disc standard) : 352×288 pixels * At a display rate of 29.97 frames per second, interlaced (commonly used in regions with 60 Hz image scanning frequency): : 720×480 pixels (same resolution as D-1) : 704×480 pixels : 352×480 pixels (same as the China Video Disc standard) : 352×240 pixels The following formats are allowed for MPEG-1 video: * 352×288 pixels at 25 frame/s, progressive (Same as the VCD Standard) * 352×240 pixels at 29.97 frame/s, progressive (Same as the VCD Standard) Video with 4:3 frame aspect ratio is supported in all video modes. Widescreen video is supported only in D-1 resolutions. The MPEG-1 Part 2 format does not support interlaced video. The H.262/MPEG-2 Part 2 format supports both interlaced and progressive-scan content. Content with a frame rate different from one of the rates shown above can be encoded to H.262/MPEG-2 Part 2 by using pulldown. This is most commonly used to encode 23.976 frame/s content for playback at 29.97 frame/s. Pulldown can be implemented directly while the disc is mastered, by actually encoding the data on the disc at 29.79 frames/s; however this practice is uncommon for most commercial film releases, which provide content optimized for display on progressive scan television sets. Alternately, the content can be encoded on the disc itself at one of several alternate frame rates, and use flags that identify scanning type, field order and field repeating pattern. Such flags can be added in video stream by the H.262/MPEG-2 Part 2 encoder. A DVD player uses these flags to convert progressive content into interlaced video in real-time during playback, producing a signal suitable for interlaced TV sets. These flags also allow reproducing progressive content at their original, non-interlaced format when used with compatible DVD players and progressive-scan television sets.〔("Home Theater High Fidelity: DVD Benchmark Part 5 Progressive Scan DVD" ).〕〔("Home Theater High Fidelity: A Beautiful Mind, Review" ).〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「DVD-Video」の詳細全文を読む スポンサード リンク
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